Process of and apparatus for applying stencil designs



April 7, 1931. H. L, RADWAY PROCESS OF AND APPARATUS FOR APPLYING STENCIL DESIGNS Filed Sept. 13, 1929 INVENTOR //Me L BY fit V 27 ATTORNEY r/q V Patented Apr, 1931 V HENRY L. IBADWAYI,I or oLEvnLANL; 01110,

PROCESS 03min ArrnnnmnsronA rPLYme sreucmnnslens i Application filed September 3, 1929; Serial No. 392 342 This invention relates to a process of and the apparatus for applying stenciljrdesigns,

"particularlytosuch process and apparatus means for holding a stencil" against a: metallic surface on which ani enameled or painted design is to be applied through the stencil,

the magnetic" means being particularly adapt- "ed to firmly hold the edges of thestencil against the surface-to prevent the paint or e'nameling fluid from creeping} under: the edges of the stencil. c

- Another object" is to' provide sucha device which, in addition toholding the'stencilin place While the design is being applied,-lis adapted to heat the surface 1y dry the stencileddesi-gn. g I I V A further object is to provide a novel procjess of applying stencil designs and the like to enameled metal ware. Withjthe above and other objects in view,the' present invention maybe said to comprise the apparatus, as illustrated in the accompanying I drawings and the-procedure of carrying; out theinvention, hereinafter: described and "particularly set forth inthei'appended claims; together. l'w'ith such variations and. modifiations there of as will be apparent to one-skilled in'the art to which theinvention appertains.

1 Inthe embodiment of the presentinvention, I J Figured is a plan vie-wot the magnetic stencil holding device,- showing the. general 7 I arrangement of I the magnet poles-I and showing fragmentary portions of a metal-member and a stencildisposed thereofvenf r v;- F 1g; '2 is "a longitudinal"sectionitaken stantiallyon the line 2+2 of Fig.1". I v 'S T-he "present invention is particularly adapted for pension Wouldnot cree I 'of thestencil; It is o vious that if'tli'e enaame'l did creepunderneat'h the edgesof the Another object is; to provide magnetic 1 in order to quick d= awings, which illustrate. a suitable I I gredients' of the, ena1nel', so that considerable time can be saved between the enameling and Vitrifying operations. Another important 1 advantage in applyingthe design to. an unburned'coat of enamel isgthat blistering of a the design enamel and the making'of water use with vitreous enameled met-V al articles; on which it is desiredi to apply a {figure or design through a stencil. 1 The :de-; sign 7 is usually: of a different color: than the enamel coati'ng'and is-appliedbefore the coatingis fused orivitrified', so that the coating an'd the design can'be fused, in a single-opera tion. The vitreous-enamel for the design usually comprises a watersiispension of finely divided oxides; and is sprayed on the enamel coating through a stenci I V I V Heretofore considerable difficulty hasbeen contact with the article thatgth'e enamel en's underneath the edges stencil the design would; have ragged, un-

fusedenamel base coat, which hasfa tendency to: absorb the design ,enamelf being applied,

'eperienc'edin holding the stencil. in such'close ,I

even edges. This is especiallytrueof the un- Furthermore, when the base coat and enamel I are. vitrifiedithe enamel which has" run underneath the edges'of the stencil" will have.

a tendency to blend in with the base coat and produce agradual fading out of color ofthe design and prevent adistinct line-of demarcation between the base coat and the design. i

The present inventionproposesamagnetic II arrangement; wh ch is adapted; toibe posi tione'd, inside the metal article to be provided with an enameled design,-which will firmly f hold all the edges of'a'metallie stencil in close Contact with the outer surface o f-the article.

' 'Vitreousfenamel asgpreviously mentioned 5 and as used forsheet metal, usually comprises a .watersusp'ension of finely divided oizides and beforetheenamel can be fused orvitrified' J the water must be evaporated] I The present invent on comp'nsesxmean's for greatly acceler'atingthe evaporation ofjthe volatile inlinesi is substantially' eliminated. 1

or any other suitablemeans, These pole Referring totheaccoinpanying drawing, in a k me l r -fe-i' i l ke. para throughout the several views, the magnet ar- I r rangement, comprises a. suitable base 101mpieces 11,

bly of such size,

, design 18, being pieces 11 are preferably of thin rectangular shape, preferably of about inch thickness, and are positioned on the base 10 in vertical parallel relationship. In order to obtain the greatestv efficiency from the device the poles 11 are preferably spaced at about one inch intervals. They may, however, be spaced as far apart as two inches or as close as half aninch. This is, of course, dependent somewhat on the size of the device and the size of the stencil tobe held. The windings13 are so arranged'that adjacent poles will be of opposite polarity, negative polarity and thetwo adj acentpoles will be of positive polarity.

The upper end faces of the pole pieces 11 are substantially flat and lie in the same horizontal plane if the device is to be .used with an article having a flat surface. However, if the article to be enameled has a curved surface the end faces of the pole pieces 11 are preferably arranged to lie in a curved plane, havingthe same general curvature as the article. Side and end pieces 14: are preferably secured to the base 10 by screws 15to completelyenclose the magnet device with the exception of the ends of the pole pieces .11 which are left exposed. l

The magnet is placed inside the article 16 to be enameled or against the side opposite theside to be enameled and the. stencil 17 .is positioned against the side to be enameled in the vicinity of the magnet. The endfacesof the pole pieces 11 all lie in the same plane, providing a suitable supportingsurface for the article 16 uponwhichthe stencil 17 of magnetic material is positioned. v 1

It is obvious that the. stencilcompletes the magnetic circuit and providesapath for-the lines of magnetic polarization 19, as shown in Fig. 2, between'opposite poles of the magnet device. It willbe observed that the pole being in rather closely spaced relationship, greatly increase the magnetic effect which causes all the edges of the stencil definingthe design 18 to be very firmly held against the surface ofthe article 16.

The enamel suspension for the design is sprayed through .the stencil 17, and it is readily apparent thattheedgesdefining the article 16, will'prevent the suspension from seeping, or otherwiselworking underneath the stencil. T It is apparent that by holding the stencil in this. way a design having a distinct .line of demarcation with respect tothe base coating of the article can be produced.

In cases where the enamel: design is applied to a metallic article hiaving an unfused base coating, theimagnetwindings13 are preferaor rather. such diameter of wire, that in addition to holding the stencil against. the article being enameled, they form resistor units that develop considerableheat. It is I readily apparent that ,theheat thrown that is one pole will be of in firm contact with the off from the windings 13 will,in this case, quickly heat the article 16 so that the volatile ingredients of the enamel suspension used in applying the design will be rapidly evaporate It is obvious that the magnet serves a dual purpose,.that of holding the stencil in position while the design is applied and of substantially simultaneously evaporating the volatile ingredients of the suspension and consequently drying the design which has been applied. In this way considerable time issavedbetween th'e stenciling and fusing operations and also storage space is dispensed with because it is unnecessary to lay the articles out so that the articles can be dried previous to the fusing operation. I f

The device described and shown in the drawing has been found in" practice to successfully hold the edgesof the stencil in close contact with the article being decorated to prevent seeping of the enameling suspension,

I and to quickly dry the enamel design which has been applied. H

Furthermore, it is to be understood that the particular forms of apparatus shown and described, and the. particular procedure set forth, are presented for purposes of explanation and illustration and that various modifications of sa1d apparatus and, procedure can .be'made without departing from my inven whereby the edges of the stencil will be'firmly 1 held against the article being'stenciled, said windlngs being of sufficient resistance; to

rapidly heat said articleland quickly vaporize the volatile ingredients of the stenciling fluid applied through said stencil. 3

' 2; The method offormmg stenciled designs on metallic articles having unfused vitreous enamel coatings, whichconsists in magnetieally holding the edges of the stencildefining the design tobe applied firmly in close contact with the enameled, surface, applying the stenciling medium through saidstencil onto said enameled surface, and simultaneously heating said surface ,tosubstantially drive off the volatile ingredients .of the stenciling medium upon the application of said medium to said surface. 1 j V 3. In a device of the class described, amagnet device for holding a magnetic stencil in close relationship with thev article" being stenciled, comprising a plurality of transversely disposed pole pieces in closely spaced relationship, having their end surfaces in substantially the same plane to support thearticle upon the pole pieces, adjacent pole pieces being of opposite polarity and the windings of said pole pieces being of sufficient resistance to heat the article being stenciled andquickly dry the surface being stenciled. I p

In testimony whereof I aflix my signature.

HENRY L. RADWAY. 

